How to make easily editable text that acts as texture or normal map for another object?
I think I finally found a reasonable solution that keeps text editable on the fly without intermediate to-mesh-converting, thanks to Kamil1064 from http://polskikursblendera.pl/forum/
The secret is in shadow baking.

Steps:


switch to Blender Render
add plane
unwrap it, add new empty texture to it
position your text object slightly above plane
add sun lamp, adjust it's angle to cast light straight down (rotation x0,y0,z0)
adjust sun lamp settings to the following: Ray Shadow, Samples: 10, Soft Size: 0.010 (if you won't, you'll have jagged sharp shadow edges instead of nice antialiasing)





select your plane and bake with settings: Bake Mode: Shadow




If everything is set properly, you will have a nice, antialiased texture that you can save for later use. The best part is, it will be easily editable from within Blender, just select text object, press TAB and edit it, then press Bake again, and voila.